Vertical axis wind turbines require guy wires for their support and continued support during operation. Particularly, the guys must withstand fluctuating loads applied thereto--the severity and disposition of the fluctuating loads dependent upon a number of parameters, including the operating speed of the rotor or rotors, temperature, wind speed, guy tension, and accumulation of ice (where existing). While attempts to overcome the problem of fluctuating loads have been made, no one proposal has been entirely satisfactory. Particularly, extremely high tensions have been applied to the guys (in the order of in excess of 16,000 pounds by Sandia Laboratories, Albuquerque, N.Mex. to elevate the natural frequency (1st mode) of the guys above the loading frequency generated by the wind turbine (two(2) per revolution). However, the increased tension decreases the efficiency of the wind turbine because of increased wear and tear to, and internal friction of, the structure.
It is therefore an object of this invention, to provide an improved control for the guys on the application of fluctuating loads.
It is a further object of this invention to provide an improved control for the guys which permits the safe operation of wind turbines, at reduced guy tensions, thereby decreasing the wear and tear to, and internal friction of, the structure. For example, the wind turbine tested by Sandia Laboratories at a guy tension of 16,000 pounds can be operated at a guy tension of 5,000 pounds.
Further and other objects of the invention will be realized by those skilled in the art from the following summary of the invention and detailed description of the preferred embodiment thereof.